/Engine/Source/Developer/AssetTools/Public/AssetViewUtils.h
Capture active viewport to thumbnail and assigns that thumbnail to incoming assets
namespace AssetViewUtils { void AssetViewUtils::CaptureThumbnailFromViewport ( [FViewport](API\Runtime\Engine\FViewport) * InViewport, const [TArray](API\Runtime\Core\Containers\TArray)< [FAssetData](API\Runtime\CoreUObject\AssetRegistry\FAssetData) > & InAssetsToAssign ) }